The relative chance of pregnancy following tubal or uterine transfer procedures.

In a 7-month study period, a total of 113 pregnancies were generated in 380 women (30%) undergoing transfers in one of four assisted conception procedures: gamete intrafallopian transfer (GIFT), pronuclear stage tubal transfer (PROST), tubal embryo stage transfer (TEST), and in vitro fertilization and embryo transfer (IVF-ET). It was shown that both the pregnancy rate per transfer procedure and the number of pregnancy sacs arising per embryo transferred were significantly higher among the groups having tubal transfer (P less than 0.001). There were no significant differences in the pregnancy or implantation rates among the three groups having tubal transfer procedures when the GIFT results were adjusted for a 72% fertilization rate noted in the combined IVF-ET and PROST groups. Early pregnancy wastage showed a similar pattern among the four groups and, overall, 67% of pregnancies advanced beyond 20 weeks.